The present invention relates to a washer-dryer apparatus such as drum-type washer-dryer apparatus and fully automatic washer apparatus and a control method therefor.
FIGS. 14 and 15 show schematic cross-sections of a conventional drum-type washer-dryer apparatus.
As shown in FIG. 14, the drum-type washer-dryer apparatus includes an outer casing 1, a water tank 4 placed in the outer casing 1, a rotation drum 5 placed within the water tank 4 and adapted to accommodate a wash, i.e., things to be washed and things washed, a transparent rigid or inflexible outside door 3, an automatic door opening/shutting mechanism 10 for automatically opening and shutting the outside door 3, and a dryer unit 24 for drying the wash.
An outer casing opening 1a is formed on a front face of the outer casing 1 is. A wash is put in and taken out through the outer casing opening 1a. The outer casing opening 1a is opened and shut by the outside door 3 that is slidable upward and downward with respect to the outer casing 1. As means for opening and shutting the outer casing opening 1a, there is also known a door mounted pivotably on a rim of the opening 1a by a hinge mechanism or the like, other than the outside door 3.
An operation panel 11 having operation keys, display units and the like is provided on an upper part of the front face of the outer casing 1. A control section 2 for controlling operation of the drum-type washer apparatus is provided on a reverse side (on the water tank 4-side) of the operation panel 11, and thus inputs into the operation panel 11 allow successive or separate performance of washing step, rinsing step, dewatering step, and drying step.
The water tank 4 is elastically supported through medium of a suspension 8. The water tank 4 has a shape of a bottomed cylinder with a water tank opening 4a that opens in face of the outer casing opening 1a. The water tank 4 is positioned transversely and slantly so that the rear side thereof (the right-hand side in the drawing) is in lower position. The water tank opening 4a and the outer casing opening 1a face each other with a space between them.
A transparent lid member 6 is mounted to the water tank 4 through a hinge mechanism, so that the water tank opening 4a can be opened and shut by the lid member. The lid member 6 is provided with a convex part 6a that protrudes toward inside of the rotation drum 5 when the water tank opening 4a is shut. A sealing member 41 is provided on an inner circumferential surface of the water tank opening 4a and, while the water tank opening 4a is shut by the lid member 6, the water tank opening 4a is held watertight by intimate contact between the sealing member 41 and the convex part 6a. 
The rotation drum 5 has a shape of a bottomed cylinder with a drum opening 5c that opens in face of the water tank opening 4a. The rotation drum 5 is positioned transversely and slantly so that the rear side thereof (right side in the drawing) is in lower position. That is, a rotation axis y-y of the rotation drum 5 is slanted so that the rear side thereof is lowered at an angle θ relative to a horizontal direction. A motor 9 is connected to a backside of the rotation drum 5 through a shaft 5e, and is driven to rotate the rotation drum 5 in accordance with control by the control section 2. A plurality of small bores 5a are provided throughout a circumferential wall of the rotation drum 5. The small bores 5a allow circulation of laundry water (water such as tap water and bath water or water containing detergent or the like), air or the like between a space between the water tank 4 and the rotation drum 5 and a space in the rotation drum 5.
An inner wall surface of the rotation drum 5 is provided with baffles 5b protruding radially inwards. The baffles 5b are provided circumferentially at three sites at intervals of 120°, for example, and repeatedly lift up and drop the wash with rotation of the rotation drum 5. While the rotation drum 5 is rotating, a fluid balancer 5d that surrounds the drum opening 5c from outside reduces unbalance caused by one-sided wash and laundry water, through agency of motions of sealed-in fluid in the fluid balancer 5d. 
The dryer unit 24, which has a blower 31 and a heater device 32, is provided on top of the water tank 4. In the dryer unit 24, the blower 31 is positioned on the rear side of the drum-type washer-dryer apparatus and the heater device 32 is positioned on the front side thereof. The blower 31 includes blower blades 34 in a casing 33 and a fan motor 35 for driving the blower blades 34 to rotate, which motor is provided outside the casing 33. The fan motor 35 is directly connected to the blower blades 34 so as to drive the blower blades 34 to rotate with use of a direct drive structure. On the other hand, the heater device 32 includes a heater 36 in a heater case 26, and an inlet part of the heater case 26 communicates with an outlet part of the casing 33 of the blower 31.
A drain valve 20 is provided below the water tank 4. The drain valve 20 is opened/shut by a drain valve motor not shown. Upon opening of the drain valve 20, water in the water tank 4 is drained through a flexible drain hose 19 to outside.
In the outer casing 1, a blower duct 38 is placed on the front side of the water tank 4. One end of the blower duct 38 communicates with an outlet part of the heater case 26 of the heater device 32, and the other end of the blower duct 38 forms a jet 38a. From the jet 38a, air heated in the heater 36 is jetted toward inside of the rotation drum 5.koko
In the outer casing 1, a dehumidifier 27 is placed on the back side of the water tank 4. With water poured into the dehumidifier 27 through an upper part thereof, the dehumidifier 27 performs dehumidification by cooling and condensing water content of air that passes therethrough. The dehumidifier 27, which is generally hollow, has a water inlet 27a and an air outlet 27b in the upper part thereof and has an air inlet 27c doubling as a water outlet in lower part. The air outlet 27b of the dehumidifier 27 communicates with inlet part of the casing 33 of the blower 31, and the air inlet 27c communicates with lower part of inside of the water tank 4. To the water inlet 27a is connected a feed water supply system not shown.
In the drum-type washer-dryer apparatus having the above configuration, a user opens the lid member 6 directly and manually, thereafter puts a wash into the rotation drum 5 through the outer casing opening 1a, and then shuts the lid member 6 directly and manually. Thus inner rim 41a of the sealing member 41 is brought into intimate contact with rim of the lid member 6 so that the water tank 4 is sealed. When the user manipulates the operation panel 11 so as to start a washing operation based on instruction from the control section 2, the automatic door opening/shutting mechanism 10 initially slides the outside door 3 in an upward direction in the drawing along a front panel 7. Then the outside door 3 shuts the outer casing opening 1a, as shown in FIG. 15, while making a track generally shaped like an arc. Upon termination of the washing operation, subsequently, the automatic door opening/shutting mechanism 10 slides the outside door 3 in a downward direction in the drawing along the front panel 7. Thus the outer casing opening 1a is opened again as shown in FIG. 14. After that, the user opens the lid member 6 directly and manually and subsequently takes the wash out of the rotation drum 5.
In a drying operation, the fan motor 35 drives the blower blades 34 to rotate, and the heater 36 is energized. Thus air jetted from the blower 31 is heated to a high temperature by the heater 36 while passing through the heater case 26, then passes through the blower duct 38, the jet 38a, and the drum opening 5c, and collides with and dries the wash in the rotation drum 5. The hot humid air having absorbed moisture from the wash in the rotation drum flows through the small bores 5a provided on the circumferential wall of the rotation drum 5, into the space between the rotation drum 5 and the water tank 4. The space communicates with a space in the dehumidifier 27. Therefore the hot humid air enters the dehumidifier 27, then forms dew by being cooled by cold water flowing through the dehumidifier 27, and thereby undergoes dehumidification. The air dehumidified by the dehumidifier 27 is forwarded afresh by the blower 31 to the heater 36, heated in the heater 36, and then delivered into the rotation drum 5. In this manner, a process of drying the wash in the rotation drum 5 is carried out.
In the conventional drum-type washer-dryer apparatus, however, foreign matter such as flue produced from a wash and circulated with air in the drying step is not eliminated. Accordingly, such foreign matter may adhere to a shaft (not shown) linking the blower blades 34 to the fan motor 35 and may thus form a resistance against rotation of the blower blades 34 and the shaft.
As a result, degradation in blowing capacity of the blower 31 may lead to degradation in drying capacity such as elongation in time required for drying.
As a method for preventing the foreign matter from entering the blower blades 34, a method is conceivable in which a filter for trapping the foreign matter is provided on the upstream side of the inlet part of the casing 33 of the blower 31.
Even though the filter is provided, however, repetition of the drying steps may lead to clogging of the filter with the foreign matter and may result in degradation in suction capacity of the blower 31.
Consequently, a user has to clean the filter each time the filter is clogged and there occurs a problem of increase in burden on user.